Electrical insulation cutter



Jan. 16, 1940. sp o 2,187,215

ELECTRICAL INSULATION CUTTER Filed May 16, 1938 Jada/W Mai? S O/heJ/o Patented Jan. 16 1940 UNITED" STATES- PATENT OFFICE 2,187,215 ELECTRICAL. INSULATION. CUTTER Matti Spinello,. Rockford, 111.,

half to Lemuel'J. Wood;

assignor of one- Rockford, Ill.

Application May I6; 1938; Serial No. 208,200

8 Claims.

I Thisinvention relatesto a tool for cutting and removing insulation covering andinsulation from electric wires. i

1 Electricians and linemen have been accustomed to using pocket'kni-ves for cutting the ;-t'oo1 much timetox makethe adjustment and obviously the workman would feel. that unless he couldsave time over the. old method there was no object in the purchase of a special: tool for that purpose; Furthermore; most ot the tools proposed were intended only for cutting the covering t and theworkman wouldstillihavei-to resort to the a 25 pocket knife to removethe insulation. It is therefore the: principal. object of. my invention to provide a quickly adjustable tool designed to do both operationsythe same having a blade which in one position works in a Vr-shaped guide to out the covering, the blade being: adjustable quickly to suit the depth of cut to. be made, and

i which in, another position projects outside the i guide and is adaptedin such position tocirvthe cndof the wire.

cumscribe the insulation and be usedainpulling the shortsection of insulation thus severed olf The invention is illustratedin theraccompanying drawingin whichonthe line 656' of Fig; 5. i i q The same reference numerals are applied to Figures l and} are a side and front view of the tool of my invention illustrated in the act of cutting the covering of a duplex wire;

Fig. 3 is a view similar to Figure l but showing the blade in anlcxtreme position of adjustment projecting from the Vguide to'remove the insulation fromone of the inner wires;

Fig 4 is a bottom view, and Fig. 5 -an e nd view of the tool, and l i i Fig. 6 is a longitudinal section. through the tool corresponding partsthroughout theviewsr it Theitool comprises-a handle I of wood rubber, or any composition material, channel shaped in cross-section and, havingmounted inthe channel lth ereof a channels-shaped sheet metal blade holder 8, the side walls of which are parallel'for the major portion of the length of the holder but at one end are bent outwardly away from one another to providea V guide 9' to cooperate with the hook-shaped cutting end ill of the blade H. The blade ll has a: free working fit betweenthe sidewalls of the channehshaped holder 8', and is mounted for pivotal. movement on abolt l2 en tered through registering holes'in the handle i and bladefiholder' B and: having a nut I3 threaded on one end thereof topretain' the same in place. i

The end ofthev blade holder 8= remote from the V guide 9 has the side wallslthereof spread apart to the diverging relationship indicated at Min Fig. 4 so as to provide a wide enough throat or slot I 5 in the rear end off the blade: holder for adjustmentof the tail end E6 of the bladerelaa tive to a ratchet l1 formed: preferably as anexttension of one side wall of the blade holder bent inwardly substantially: at right angles toward the line with the rest of the blade H but bent about its longitudinal axis as indicated at it so that the lower edgeof saidv end portion can engage selectively with. anyone of the teeth I9 of the ratchet l1. There is sufficient springiness in the blade I! to. keep the end portion l5 securely en gaged with the ratchet in any position of adjustment but one can readily and quickly shift the end portion up or'down to'some other position by simply pressing the end portion i6", out of engagement with the ratchet andfithen moving ittoxthe position desired, whereupon itwill spring back into engagement with the ratchet to look the blade in the new position. 1 In operation, when the blade H is adjusted to cut to the proper depth, the V-shaped front end of the tool is placedjover the wire as indicated in Figs. 1 and 2, and the covering 29 is cut lengthwise by movement of l the tool along the wire.

After the covering is slitted it can be laid back lto expose the inner wires 21 and 22 and cut or torn on. In cutting it oif, one may use the blade H in the position shown in 3 and run the hooked end of the blade, which is sharpened along twosides of a V as indicated at 23 and 24,

circumferentially around the wire to sever the slitend section of covering fromthe rest of the wire.

position, one can also useit to cut oil the insulation from the inner wires 2! and 22 as shown'in Fig. 3, the operation here being similar to that described ,for cutting thc covering 20 circunm ferentiaily. Once the insulation has been cut completely around the wire, the workman can Then, with the blade 1| still in this same 2 t end lfi of the blade H. The end portion 56 isin use the hooked end I0 of the blade conveniently in pulling off the severed end portion of insulation from the wire. It is evident, therefore, that with the present tool one can do all of the operations required and the blade can be moved from one position to another'so quickly that the electrician saves considerable time in working with this tool as compared with using a pocket knife. When the tool is not in use the hooked end ll! of the blade will be in a retracted position so that there is no danger of cutting ones self or having the tool damaged by contact with other tools in a tool box. The tool is furthermore made small enough so that it can be carried in the pocket so as to be just as handy and ready for use as the pocket knife, It is furthermore obvious that the construction is such that the tool can be made at very low cost and will be extremely serviceable.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn with a view to covering all legitimate modifications and adaptations.

I claim:

1. A tool for cutting and stripping insulation from electric wires comprising an elongated blade holding handle, the same having a V guide at one end thereof, an elongated blade pivotally mounted intermediate the ends thereof on said handle and having a cutting end movable in said V guide, the other end of said blade projecting from said handle and being flexible laterally relative to the handle manually for locking and unlocking the same with respect to the handle and means for quickly releasably locking said blade by said manually operable flexible end in fixed relation to the handle.

2. A tool for cutting insulation on electric wires comprising an elongated blade holding handle having a V guide at one end thereof, an elongated blade pivotally mounted intermediate the ends thereof on said handle and having one end constructed for cutting the insulation and the other end projecting from the adjacent end of the handle for manual oscillatory adjustment of the blade, the blade being so formed and pivoted that the cutting end is not only adjustable in respect to the amount it projects into the V guide, so as to determine the depth of cut in slitting insulation, but is also adjustable to an extreme position where substantially the entire cutting end projects out of the V guide end of the handle so as to adapt the same for use in cutting insulation circumferentially with respect 'to a wire, and means cooperating with the manually operable end of the blade for locking said blade releasably in adjusted position. 1

3. A tool for cutting insulation on electric wires comprising an elongated blade holding handle having a V guide at one end thereof, an elongated blade pivotally mounted intermediate the ends thereof on saidhandle and having one end constructed for cutting the insulation and the other end projecting from the adjacent end of the handle for manual oscillatory adjustment of the blade, the blade being so formed and pivoted that the cutting end is not only adjustable in respect to the amount it projects into the V guide, so as to determine the depth of cut in slitting insulation, but is also adjustable to an extreme position Where substantially the entire cutting end projects out of the V guide end of the handle so as to adapt the same for use in cutting insulation circumferentially with respect to a wire, and means for releasably locking the blade in adjusted position.

4. A tool of the character described comprising an elongated channel-shaped sheet metal blade holder-having the side walls at one end thereof bent outwardly in diverging relation to form a V guide adapted to receive an electric wire in running the tool lengthwise of the wire to slit the insulation covering thereon, an elongated flat blade having a close working fit between the side walls of the holder and pivoted intermediate the ends thereof in the holder for oscillatory movement so as to adjust one end of the blade outwardly from the apex of. the V guide according to the depth of cut to be made, said end having a cutting edge thereon adapted for slitting insulation covering on a wire, the other end of the blade protruding from the adjacent end of the holder for manual adjustment of the blade, the adjacent end of said holder having one of its side walls bent in diverging relation to the other side wall to permit lateral deflection of the manually adjustable end of the blade in the holder to and from a locked position of adjustment, and means on one side wall of said holder for releasably securing the last-named end of said blade in adjusted position relative to the holder.

5. A tool of the character described comprising an elongated channel-shaped sheet metal blade holder having the side walls at one end thereof bent outwardly in diverging-relation to form a V guide adapted to receive an electric wire in running the tool lengthwise of the wire to slit the insulation covering thereon, an elongated flat blade having a close working fit between the side walls of the holder and pivoted intermediate the ends thereof in the holder for oscillatory movement so as to adjust one end of the blade outwardly from the apex of, the V guide according to the depth of cut to be made, said end having a cutting edge thereon adapted for slitting insulation covering on a wire, the other endof thev blade protruding from the adjacent end of the holder for manual adjustment of the I blade, the last named end of the blade holder having an inturned flange, the edge of which is formed to provide a ratchet, and the last named end of the blade having a lower edge portion normally engaging the ratchet to hold the blade in adjusted position, said blade end being spring pressed toward engagement with the ratchet but being movable out of engagement therewith manually to permit adjustment of, the blade as desired.

6. A tool of the character described comprising an elongated channel-shaped sheet metal blade holder having the side walls at one end thereof bent outwardly in diverging relation to form a V guide adapted to receive an electric wire in running the tool lengthwise of'the wire to slit the insulation covering thereon, an elongated flat blade having a close working fit between the side walls of the holder and pivoted intermediate the ends thereof in the holder for oscillatory movement so as to adjust one end of the blade outwardly from the apex of the V guide according to the depth of cut to be made, said end having a cutting edge thereon adapted for slitting insulation covering on a wire, the other end of the blade protruding from the adjacent end of the holder for manual adjustment of the blade, the last named end of the blade holder being formed so that the end portions of the side walls thereof diverge so as to form a Wide enough throat to permit laterally springing the last named end of the blade, the last named end of the blade being twisted into acute angled relationship to the rest of the blade, and one side wall of the blade holder having the end portion thereof formed to provide an inwardly bent flange, the edge of which is further formed to provide a ratchet for engagement with the lower edge of the twisted end portion of the blade, the twisted end portion of the blade being normally disposed in engagement with the ratchet to hold the blade in adjusted position but being springable laterally out of engagement with the ratchet to permit oscillatory adjustment of the blade.

7. A tool of the character described comprising an elongated channel-shaped sheet metal blade holder having the side walls at one end thereof bent outwardly in diverging relation to form a V guide adapted to receive an electric wire in running the tool lengthwise of the wire to slit theinsulation covering thereon, an elongated flat blade having a close working fit between the side walls of the holder and pivoted intermediate the ends thereof in the holder for oscillatory movement so as to adjust one end i of the blade outwardly from the apex of the V guide according to the depth of cut to be made, saidend having a cutting edge thereon adapted for slitting insulation covering on a wire, the other end of the blade protruding from the adjacent end of the holder for manual adjustment of the blade, means for, releasably securing the blade in adjusted position, handle grip means for engagement: with the opposite side walls of the blade holder, and a bolt e2;-

mediate pivot for the blade.

tending throughregistering holes in the handle grip means and the side walls of the holder and also in the blade whereby to secure the handle means to the holder and also provide the inter- 8. A tool of the character described comprising an elongated channel-shaped sheet metal blade holder having the side walls at one end thereof bent outwardly indiverging relation to form a V guide adapted to receive an electric wire in running the tool lengthwise of the wire to slit the insulation covering thereon, an elongated fiat blade having a close working fit between the side walls of the holder and pivoted intermediatethe ends thereof in the holder for oscillatory movement so as to adjust one end of the blade outwardly from the apex of the V guide according to the depth of cut to be made, said end having a cutting edge thereon adapted for slitting insulation covering on a wire, the other end of the blade protruding from the adjacent end of the holder for manual adjustment of the blade, means for releasably securing the blade in adjusted position, a handle of channelshaped cross-section fitting over the blade holder with the side walls thereof in abutment with the outside of the side walls of said blade holder, and a single bolt extending through registering holes provided in the side walls of the handle and blade holder and also in the blade whereby to secure the handle to the holder and also provide the pivot for the blade.

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